In a cordless electric tool, a battery pack for feeding power to a motor, which is a driving source, is detachably mounted to the tool. The battery pack has therein a secondary battery such as a chargeable lithium battery and the like. The battery pack is mounted to a lower end portion (a battery attachment part) of a housing handle part, for example, by sliding the battery pack along a rail part in a horizontal direction (see, for example, JP-A-2002-260619).